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DIGITAL TERRESTRIALTELEVISIONBROADCASTING

IEEE Press445 Hoes Lane

Piscataway, NJ 08854

IEEE Press Editorial BoardTariq Samad, Editor in Chief

George W. Arnold Vladimir Lumelsky Linda Shafer

Dmitry Goldgof Pui-In Mak Zidong Wang

Ekram Hossain Jeffrey Nanzer MengChu Zhou

Mary Lanzerotti Ray Perez George Zobrist

Kenneth Moore, Director of IEEE Book and Information Services (BIS)

Technical Reviewers

Xinyi Liu, Hong Kong Applied Science and Research InstitutePablo Angueira, University of the Basque Country

DIGITAL TERRESTRIALTELEVISIONBROADCASTING

Technology and System

Edited by

JIAN SONGZHIXING YANGJUN WANG

Copyright 2015 by The Institute of Electrical and Electronics Engineers, Inc.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey. All rights reservedPublished simultaneously in Canada

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CONTENTS

Preface xiii

1 Basic Concepts of Digital Terrestrial Television TransmissionSystem 1

1.1 Introduction and Historic Review, 11.1.1 Birth and Development of Television Black-and-White

TV Era, 11.1.2 Analog Color TV Era, 21.1.3 Digital TV Era, 3

1.2 Major International and Regional DTV Organizations, 71.2.1 International DTV Broadcasting Standards, 71.2.2 Related International and Regional Organizations, 9

1.3 Composition of DTV System, 111.3.1 Constitution of DTV System, 111.3.2 Functional Layers of DTV, 14

1.4 Compression Layer and Multiplexing Layer, 191.4.1 Image Format, 191.4.2 Compression Modes for DTV Signal, 191.4.3 MPEG-2 for Video Compression, 201.4.4 Intraframe Coding, 211.4.5 Interframe Coding Method, 231.4.6 Audio Compression, 241.4.7 MPEG-2 Coding, 251.4.8 MPEG-2 Multiplexing, 261.4.9 Transport Stream, 26

v

1.5 Current Deployment of DTTB Systems, 291.5.1 Developments of ATSC, DVB-T, and ISDB-T, 301.5.2 Development and Deployment of DTMB System, 331.5.3 Network Convergence with DTTB Systems, 35

1.6 Summary, 37References, 37

2 Channel Characteristics of Digital Terrestrial TelevisionBroadcasting Systems 39

2.1 Introduction, 392.2 Mathematical Models of Wireless Radio Channel, 42

2.2.1 Statistical Model of Channel Impulse Response, 422.2.2 Channel Impulse Response with Deterministic Parameters, 44

2.3 Property of Wireless Fading Channel Parameters, 462.3.1 Multipath Delay Spread and Frequency-Selective Fading, 462.3.2 Doppler Shift and Time-Selective Fading, 502.3.3 Time- and Frequency-Selective Fading of Wireless Radio

Channel, 542.4 Commonly Used Statistical Models for Fading Channel, 55

2.4.1 Rayleigh Fading Model, 552.4.2 Ricean Fading Model, 56

2.5 DTTB Channel Model, 582.5.1 Typical DTTB Channel Model, 582.5.2 Single-Frequency Network of Channel Model for DTTB

Systems, 632.6 Summary, 67References, 68

3 Channel Coding for DTTB System 69

3.1 Channel Capacity and Shannon’s Channel Coding Theorem, 693.2 Error Control and Classification of Channel Coding, 733.3 Linear Block Code, 75

3.3.1 Basic Concept of Linear Block Code, 753.3.2 BCH Code, 783.3.3 Reed–Solomon Code, 79

3.4 Convolutional Codes, 803.4.1 Construction and Description of Convolutional Codes, 813.4.2 Distance Property and Decoding of Convolutional Codes, 84

3.5 Interleaving, 873.5.1 Block Interleaving, 873.5.2 Convolutional Interleaving, 88

3.6 Concatenation Codes, 893.7 Parallel Codes, 92

3.7.1 Product Codes, 92

vi CONTENTS

3.7.2 Turbo Codes and Iterative Decoding, 943.8 Trellis Coding and Modulation, 100

3.8.1 Mapping by Set Partition of TCM Codes, 1003.8.2 Code Construction and Basic Principles of TCM Codes, 101

3.9 Low-Density Parity-Check Code, 1033.9.1 Basic Concept of LDPC Codes, 1043.9.2 Decoding Algorithms of LDPC Codes, 106

3.10 Channel Coding Adopted by Different DTV BroadcastingStandards, 108


4 Modulation Technologies for DTTB System 113

4.1 Introduction, 1134.2 Digital Modulation, 114

4.2.1 Signal Space and Its Representation, 1144.2.2 Typical Digital Modulations, 1174.2.3 The Power Spectrum of Modulated Signal, 1244.2.4 Demodulation and Performance Evaluation, 1294.2.5 Variations of Digital Modulations, 137

4.3 Bit-Interleaved Coded Modulation, 1404.3.1 BICM System Model, 1404.3.2 BICM Design and Performance Evaluation, 1414.3.3 BICM-ID System Model, 1444.3.4 BICM-IDwithDoping:Design andPerformanceEvaluation, 1454.3.5 BICM-ID Design Based on EXIT Charts, 1464.3.6 BICM-ID with LDPC Coding, 147

4.4 Multicarrier Modulation, 1484.4.1 Principle of Orthogonal Frequency Division Multiplexing, 1494.4.2 Implementation of OFDMwith Discrete Fourier Transform, 1514.4.3 Guard Interval and Cyclic Prefix of OFDM, 1524.4.4 Frequency Domain Property, 1564.4.5 General Comparison between OFDM and Single-Carrier

Modulation System, 1574.5 Design Considerations of DTTB Modulation, 159

4.5.1 Modulation Scheme Determination, 1594.5.2 Modulation Schemes in Typical DTTB Standards, 160


5 First-Generation DTTB Standards 163

5.1 General Introduction, 1635.1.1 ATSC Standard, 1635.1.2 DVB-T Standard, 164

CONTENTS vii

5.1.3 ISDB-T Standard, 1645.1.4 DTMB Standard, 164

5.2 Introduction to ATSC Standard, 1645.2.1 Scrambler, 1665.2.2 RS Encoding and Data Interleaving, 1675.2.3 TCM Encoder and Interleaver, 1685.2.4 Multiplexing, 1695.2.5 Pilot Insertion and VSB Modulation, 170

5.3 Introduction to DVB-T Standard, 1715.3.1 Channel Coding, 1735.3.2 Modulation, 176

5.4 Introduction to ISDB-T Standard, 1805.4.1 Multiplexing, 1845.4.2 Channel Coding, 1855.4.3 Constellation Mapping and Modulation, 1865.4.4 TMCC Information, 194

5.5 Introduction to DTMB Standard, 1955.5.1 Major System Parameters, 1975.5.2 Input Data Format, 1985.5.3 Scrambler, 1985.5.4 FEC Coding, 1985.5.5 Constellation Mapping, 2015.5.6 Interleaving, 2035.5.7 System Information, 2055.5.8 Signal Frame Structure, 2065.5.9 Frame Header (FH), 2075.5.10 Frame Body Data Processing, 2095.5.11 Baseband Signal Post Processing, 2105.5.12 RF Output Interface, 2105.5.13 System Payload Data Throughput, 213


6 Second-Generation DTTB Standards 215

6.1 Introduction to Second-Generation Digital Video Broadcasting, 2156.1.1 System Structure, 2176.1.2 Input Processing, 2176.1.3 Bit-Interleaved Coding and Modulation, 2206.1.4 Frame Builder, 2266.1.5 OFDM Symbol Generation, 228

6.2 Introduction to DTMB-A System, 2356.2.1 System Architecture, 2356.2.2 Interface and Data Preprocessing, 2366.2.3 Scrambling, Interleaving, and Modulation, 238

viii CONTENTS

6.2.4 Superframe Structure, 2456.2.5 Signal Frame, 2476.2.6 Synchronization Channel, 2486.2.7 Transmit Diversity, 2516.2.8 Baseband Postprocessing, 2526.2.9 RF Signal, 2526.2.10 Baseband Signal Spectrum Characteristics and Spectrum

Mask, 2526.2.11 System Payload Data Rate, 253


7 Design and Implementation of DTV Receiver 255

7.1 Introduction, 2557.2 Mathematical Principles, 259

7.2.1 Channel Synchronization, 2597.2.2 Channel Estimation, 262

7.3 Single-Carrier Systems, 2697.3.1 Timing Synchronization, 2697.3.2 Carrier Synchronization, 2727.3.3 Channel Estimation and Equalization, 276

7.4 Multicarrier Systems, 2807.4.1 Timing Synchronization, 2807.4.2 Carrier Synchronization, 2807.4.3 Channel Estimation/Equalization for OFDM System, 285

7.5 Introduction to DTMB Inner Receiver, 2887.5.1 Frame Synchronization, 2897.5.2 Carrier Synchronization, 2917.5.3 Channel Estimation and Equalization, 292


8 Network Planning for DTTB Systems 299

8.1 Introduction, 2998.2 Basic Concepts, 300

8.2.1 Carrier-to-Noise Ratio, 3008.2.2 Minimal Field Strength, 3008.2.3 Cliff Effect, 3018.2.4 Location Coverage Probability, 3018.2.5 Protection Ratio, 302

8.3 Analog and Digital TV Broadcasting, 3038.3.1 Comparison between Analog and Digital

Transmissions, 3038.3.2 Frequency Planning for Terrestrial Broadcasting, 303

CONTENTS ix

8.3.3 Simulcast of Digital and Analog TV, 3048.3.4 Frequency Utilization of Terrestrial Broadcasting, 305

8.4 Multiple-Frequency and Single-Frequency Networks, 3068.4.1 Introduction to MFN, 3068.4.2 Introduction to SFN, 3078.4.3 Classification of SFNs, 3088.4.4 Interference Analysis of SFN, 3098.4.5 Synchronization in SFN, 3108.4.6 Network Gain in SFN, 3128.4.7 Application of SFN, 314

8.5 Transmission System of DTTB, 3148.5.1 DTTB Transmitter System, 3168.5.2 DTTB Exciter, 3188.5.3 Power Amplifier, 3218.5.4 Multiplexer, 3228.5.5 Transmitting Antenna, 325

8.6 Signal Reception of DTTB, 3278.6.1 Main Impact Factors of Physical DTTB Channel, 3278.6.2 Fixed Reception, 3288.6.3 Portable Reception, 3288.6.4 Mobile Reception, 329

8.7 Diversity Techniques, 3298.7.1 Various Diversity Schemes, 3298.7.2 Design Principles of Diversity Schemes for DTTB System, 3308.7.3 Transmit Diversity Technique, 3318.7.4 Receiving Diversity, 337


9 Performance Measurement on DTTB Systems 345

9.1 Introduction, 3459.2 Measurement Description, 345

9.2.1 BER Measurement and Decision Threshold, 3469.2.2 C/N Measurement, 3509.2.3 Input Signal Level to the Receiver, 3519.2.4 Interface Parameters, 3519.2.5 Multipath Models, 3519.2.6 Laboratory Test, 351

9.3 Laboratory Test Plan Using DTMB System as Example, 3549.3.1 Laboratory Test Platform, 3549.3.2 Interface Setup of Test Platform, 3559.3.3 C/N Threshold under Gaussian Channel, 3559.3.4 Minimum Reception Level in Gaussian Channel, 3579.3.5 Maximum Reception Level, 359

x CONTENTS

9.3.6 C/N Threshold in Ricean Channel, 3609.3.7 C/N Threshold in Rayleigh Channel, 3619.3.8 Maximum Doppler Frequency Shift in Dynamic Multipath

Channel, 3629.3.9 Maximum Delay Spread in Two-Path Channel with 0-dB

Echo, 3649.3.10 C/N Threshold in Two-Path Channel with 0-dB Echo, 3659.3.11 Maximum Pulse Width of Impulse Noise Interference, 3669.3.12 C/I Measurement with Cochannel and Adjacent-Channel

Analog TV Signal Interference, 3689.3.13 C/I Measurement with Cochannel and

Adjacent-Channel DTV Signal Interference, 3719.3.14 C/I Measurement with Single-Tone Interference, 3729.3.15 Antiphase Noise Measurement, 375

9.4 Field Test Plan, 3769.4.1 Field Test, 3769.4.2 Objectives of Field Test, 3779.4.3 Testing Signal, 3799.4.4 Antenna, 3799.4.5 Measurement Time, 3809.4.6 Channel Characteristic Recoding, 3819.4.7 Test Location, 3819.4.8 Test Calibration, 3819.4.9 Records and Documents, 3819.4.10 Test: Instruments and Auxiliary Equipment, 3829.4.11 Coverage Test Procedure, 3839.4.12 Service Test Procedures, 3869.4.13 Measurement Guideline of Field Test for

DTTB System, 3899.4.14 Field Test Platform, 3909.4.15 Procedure for Fixed Reception Test, 3909.4.16 Mobile Test, 391


10 Digital Mobile Multimedia Broadcasting Systems 393

10.1 Introduction, 39310.2 DVB-H System, 395

10.2.1 Block Diagram of DVB-H System, 39610.2.2 Technical Features of DVB-H System, 397

10.3 ATSC-M/H System, 40210.3.1 Frame Structure of ATSC-M/H System, 40310.3.2 ATSC-M/H System Block Diagram, 40310.3.3 Frame Encoding of ATSC-M/H System, 405

CONTENTS xi

10.3.4 Block Processor of ATSC-M/H System, 40610.3.5 ATSC-M/H Trellis Encoder, 406

10.4 CMMB System, 40810.4.1 Frame Structure of CMMB System, 40810.4.2 Channel Coding of CMMB System, 40810.4.3 CMMB Byte Interleaving, 40910.4.4 Modulation Scheme of CMMB System, 41110.4.5 Payload Data Rate of CMMB System, 411

10.5 DVB-NGH, 41310.5.1 Alamouti Scheme, 41510.5.2 eSFN Scheme, 41610.5.3 eSM-PH Scheme, 41910.5.4 Hybrid System, 422


Index 427

xii CONTENTS

PREFACE

The goal of this book is to serve as a comprehensive reference book for readers in thefield of electronic engineering with a background in digital signal processing andtelecommunications (only fundamentals and not necessarily with advanced knowl-edge in this area). The target readers include researchers, engineers, service providers,market analyst, policy makers, and IT staff who work in the digital video broadcastingarea. The book may serve as a textbook for undergraduate courses of one semester orshort courses if the instructor only focuses on the fundamental concepts and as agraduate textbook if details need to be addressed. It can also serve as a continuingeducation textbook for those in the DTV industry who want to obtain the latestupdates.

Chapter 1 introduces the basic concepts of the digital television (DTV) system,including a historical perspective and the constitution of the DTV system withemphasis on the terrestrial broadcasting system. Chapter 2 presents the characteristicsof the harsh terrestrial transmission environment for DTV signals, including propa-gation loss, the “shadow effect” by terrain factors, the multipath effect, and theDoppler effect when transmitters and/or receivers are under mobility. Chapter 3covers the fundamentals of channel coding, including interleavers that help convertburst errors into random errors for better error correction capability, especially thosebeing adopted in the digital television terrestrial broadcasting (DTTB) system.Chapter 4 mainly introduces the modulation techniques in various DTTB systems.The basic concepts of coded modulation, which jointly optimizes channel coding anddigital modulation to best control errors by nonideal effects for transmission are alsoaddressed. Chapter 5 provides information on the frame structure, channel coding,

xiii

modulation, and major parameters of the existing first-2 generation internationalstandards, especially for the newly developed digital television/terrestrial multimediabroadcasting (DTMB) system. Chapter 6 gives general information on the secondgeneration of the DTTB system, which can provide over 30% increase in datathroughput by adopting higher constellation mapping and longer coding length forbetter error correction capability. Chapter 7 focuses on the design and implementationissues of the DTV receiver, including carrier synchronization, timing recovery,channel estimation, equalization, decoding, and de-interleaving, with concreteimplementation examples of these algorithms. Chapter 8 addresses issues such ascoverage and network planning of DTTB networks with a detailed introduction of thesingle-frequency network (SFN). A brief introduction of the characteristics andimplementation of the diversity technology is also provided. Chapter 9 gives ageneral description of the system-level performance test of the DTTB systems,including the physical meaning of the test item, test methodologies/procedures,and for information purposes the test requirements using DTMB as an example.Chapter 10 describes the technical features in detail of four multimedia mobilebroadcasting systems. Even though some systems are out of favor nowadays duemainly to the spectrum issue and the tough competition, the featured technologies ofthose systems have been adopted by other systems.

With 10 chapters and quite broad topics, the instructor may arrange the topics indifferent ways depending on the time length of the course. Chapter 2 is more physicsrelated while Chapters 3 and 4 provide fundamentals of coding and modulation. Thesethree chapters, together with Chapters 5, 6 and 10, can help readers better understandthe major design issues and constraints of the DTTB systems. If the targeting audienceis interested in knowing receiver design, Chapter 7 and some of the references canserve this purpose, and network planning is addressed for service providers. Forengineers whose job function is testing, Chapter 9 provides a good topic forcontinuing education purposes.

The authors of this book have actively been involved with fundamental research onthe core technologies of DTTB systems (i.e., time-domain synchronous OFDM, TDS-OFDM), hardware implementation and the performance validation of the DTTBreceiver (more specifically, the DTMB receiver), and the international standardizationprocess, and some technical context directly comes from their research and develop-ment work. This valuable experience has motivated the authors to write this book andshare their research results and comprehensive understanding of the DTTB systemwith readers who work in this area.

The authors would like to express their sincere appreciation for the contributions ofDr. Nim Cheung. Without his kind recommendation, encouragement, and always on-time help, this book would not have been completed. The book is a joint effort ofresearchers working at Tsinghua University, China. The authors are indebted toProfessor Jintao Wang, Professor Chao Zhang, Professor Changyong Pan, ProfessorZhaocheng Wang, Professor Fang Yang, Professor Yonglin Xue, Professor KewuPeng, Professor Yu Zhang, Professor Hui Yang, Dr. Qiuliang Xie, and other teammembers for their much valuable contributions.

xiv PREFACE

The authors would also like to thank all the comments from the reviewers of thisbook proposal as well as this book. Their much valuable comments and suggestionsallowed us to better choose and arrange all the context of the book. Finally, we alsothank the great help and patience fromMary Hatcher and Brady Chin of JohnWiley &Sons, Inc. Without their kind guidance and assistance, it would have taken muchlonger with more painful effort to finish the book.

PREFACE xv

1BASIC CONCEPTS OF DIGITALTERRESTRIAL TELEVISIONTRANSMISSION SYSTEM

1.1 INTRODUCTION AND HISTORIC REVIEW

Television is a word of Latin and Greek origin meaning “far sight.” In Greek, telemeans “far” while visio is “sight” in Latin. A television (TV) system transmits bothaudio and video signals to millions of households through electromagnetic waves andis one of the most important means of entertainment as well as information access.With the never-ending technological breakthroughs and the continuously increasingdemands of audio and video services, the TV system has evolved over generationswith several important developmental periods in less than a century.

1.1.1 Birth and Development of Television Black-and-White TV Era

In the mid-1920s, the Scottish inventor John Logie Baird demonstrated the successfultransmission of motion images produced by a scanning disk with the resolution of 30lines, good enough to discern a human face. In 1928, the first TV signal transmissionwas carried out in Schenectady, New York, and the world’s first TV station wasestablished by the British Broadcasting Corporation in London eight years later. AfterWorld War II, the black-and-white TV era began. Detailed technical and implemen-tation specifications of TV service, including photography, editing, production,broadcasting, transmission, reception, and networking, were gradually formulated.With the ever-growing popularity of TV viewers, the color TV with better watchingexperience was invented to simulate the real world.

1

Digital Terrestrial Television Broadcasting: Technology and System, First Edition. Edited by Jian Song,Zhixing Yang, and Jun Wang. 2015 by The Institute of Electrical and Electronics Engineers, Inc. Published 2015 by John Wiley & Sons, Inc.

1.1.2 Analog Color TV Era

In 1940, Peter Carl Goldmark with CBS (Columbia Broadcasting System) Labinvented a color TV system known as the field-sequential system. This systemoccupied an analog bandwidth of 12MHz and was carried by 343 lines (∼100 linesless than that of the black-and-white TV) at different field scan rates, and hence wasincompatible with black-and-white TV. The system started field trial broadcast in1946, and this is the dawn of the color TV age.

In the 1950s, a color TV signal system called NTSC (National TelevisionStandards Committee) was developed in the United States that was compatiblewith the black-and-white TV. This scheme uses a luminance–chrominance encodingscheme with red, green, and blue (RGB) primary signals encoded into one luminancesignal (Y) and two quadrature-amplitude-modulated color (or chrominance) signals(U and V), and all are transmitted at the same time. An NTSC TV channel occupies6MHz bandwidth with the video signal transmitted between 0.5 and 5.45MHzbaseband. The video carrier is 1.25MHz and the video carrier generates two side-bands, similar to most amplitude-modulated signal, one above the carrier and onebelow. The sidebands are each 4.2 (5.45–1.25) MHz wide. The entire upper sidebandwill be transmitted while only 1.25MHz of the lower sideband (known as a vestigialsideband, VSB) is transmitted. The color subcarrier is 3.579545MHz above the videocarrier and quadrature amplitude modulated with the suppressed carrier while theaudio signal is frequency modulated. The NTSC system was deployed in most ofNorth America, parts of South America, Myanmar, South Korea, Taiwan, Japan, thePhilippines, and some Pacific island nations and territories. This invention isconsidered as the landmark of the second stage of the development—the analogcolor TV era.

A group of French researchers started their work in parallel and this led to theinvention of the Sequential Color with Memory (SECAM) system in 1956, and thesystem was successfully demonstrated in 1961. In the SECAM system, two colordifference signals are transmitted alternately (line by line) and frequency modulatedby the color subcarrier. This system was adopted by France, the Soviet Union, EasternEuropean countries (except for Romania and Albania), and Middle East countries andwas the first color TV standard in Europe. In 1962, Walter Bruch, a German engineerat Telefunken, put forward the Phase Alternate Line (PAL) system based on the NTSCsystem in the Federal Republic of Germany. This system performs line-by-line phaseinversion of the quadrature component of the chrominance signal in the NTSC systemand can effectively offset the phase error and increase the tolerance for differentialphase error from ±12° to ±40° in the NTSC system. This new system was adopted bymore than 120 countries successively, and in 1972 China decided to adopt it as well.

In the first 70 years of the twentieth century, even though the development of TVhad gone through two different phases (black and white and color), the fundamentalcharacteristics of TV signal transmission was unchanged, that is, the TV signal wascontinuous, or analog, and hence why both black-and-white and color TVs werecalled analog. In analog TV signal transmission, the amplitude, frequency, phase, or acombination of these parameters of the carrier are changed in accordance with the

2 BASIC CONCEPTS OF DIGITAL TERRESTRIAL TELEVISION TRANSMISSION SYSTEM

contents to be transmitted. Linear modulation as well as transmission are thereforeachieved in one step. Though simple and straightforward, the analog TV system hasthe following issues in practice [1]:

1. In terms of the quality, long-term storage, and dissemination of the videoprograms, the analog TV program source suffers from color–luminanceinterference, large-area flicker, and poor image definition, and it is difficultto replicate the content for too many times.

2. In terms of signal transmission efficiency, the analog TV network is largelyrestricted by the bandwidth available. For example, the PAL system canaccommodate only one analog video signal and one analog audio signal in8 MHz bandwidth, and the spectral efficiency is low. In addition, due tocochannel and adjacent-channel interference in neighboring areas, differentanalog channels have to be used to carry the same programs to different areas toavoid mutual interference. Therefore, the spectral efficiency is furtherdecreased, and it is very difficult to introduce new programs by assigningadditional channels in the same region due to the limited available spectrum.

3. In terms of the quality of the signal transmission, the analog TV signal maysuffer from “ghosts” from terrestrial broadcasting due to its poor anti-multipathinterference ability, which severely affects the viewer’s experience. In addition,if the analog TV signal needs to be amplified for a longer transmission distance,the noise accumulation will make the signal quality very poor due to thedeteriorating signal-to-noise ratio.

4. In terms of the circuitry, network equipment, and terminals of the analog TVsystem, the geometric distortion of images is inevitable due to the nonlinearityof the circuitry while the phase distortion of the amplifiers would cause colordeviation, aggravating the Ghost phenomenon. In addition, the analog TVsystem suffers from poor stability, time-domain aliasing, low degree ofintegration, difficulty in calibration, automatic control, and monitoring.

1.1.3 Digital TV Era

People’s demands for better audio and video quality of the TV signal has always beena tremendous driving force for the broadcasting industry, and this led to the inventionof the digital television (DTV). Also, due to significant technical breakthroughs in thedigital signal processing field (including signal acquisition, recording, compression,storage, distribution, transmission, and reception), the semiconductor industry, andother related industries in the past half century, the broadcasting industry is nowembracing the third important stage in its history, i.e. the DTV era.

The visual information received by human eyes in daily life is always analog, andthe mission of both the first and second generation of TV broadcasting systems (blackand white or color) is to transmit these analog signals to the numerous TV sets with thehighest possible quality. Although the definition or the structure of the different DTVsystems may be slightly different, the core definition or the major functional blocks

INTRODUCTION AND HISTORIC REVIEW 3

are the same. They must include the sampling, quantization, and encoding of analogTV programs to convert them into digital format before they are further processed,recorded, stored, and distributed. The sequence segmentation, scrambling, forwarderror correction coding, modulation, and up conversion are done in the baseband toform the DTV radio frequency (RF) signals after up conversion at the transmit side. Atthe receive side, after achieving the system synchronization and signal equalizationbased on accurate channel estimation, inverse operations on the received signal to thatat the transmit side will be performed before the final program can be finally displayedon the TV screen. Digital broadcasting technologies not only provide better receptionand display performances compared to its analog counterpart but also introduce newfunctions that are not available with the analog broadcasting technologies. Consider-ing all the advantages digital technology can provide over its analog counterpart, it isobvious that a DTV system can offer high-quality audio visual experiences and morecomprehensive services for consumers. Given all these featured services the DTVsystem can support, digitization is widely considered a fundamental change and newlandmark in the TV broadcasting industry, after the introduction of the black-and-white TV and the color TV.

The advantages of DTV over the traditional analog TV can be summarized asfollows:

1. Better Anti-Interference Ability, No Noise Accumulation, and High-QualitySignals. After digitization, the analog signal is changed into a binary (two-level) sequence. Unless the amplitude of the noise exceeds a certain level, noiseintroduced during processing or transmission can be effectively eliminated.Error-free transmission can also be achieved by means of forward errorcorrection coding. During transmission of the DTV signal, the quality ofthe image and sound received by the users in the coverage is almost identical tothat originally transmitted from the TV station. Thus the quality of programs inDTV would not be degraded if the system is well designed, whereas theprocessing or transmission of the analog TV signals may introduce additionalnoise which is difficult to remove, and the quality of the image and sound willthus be gradually degraded due to the noise accumulation.

2. Higher Transmission Efficiency and More Flexibility in Multiplexing. DigitalTV broadcasting can utilize the precious spectrum resources more efficiently.Using terrestrial broadcasting as an example, DTV can use the so-called taboochannel, which is not allowed in analog TV systems, and adopt the single-frequency network (SFN) technology. When SFN is adopted, the same DTVchannel can be used to carry the same TV programs with different transmittersto cover a very large area (even the countrywide SFN is possible). Dependingon the video coding compression scheme used in a DTV system, one analog TVchannel can at least contain one HDTV (high-definition TV) program, or ∼10SDTV (standard-definition TV) programs, or more than 20 DTV programs withVHS quality. Digital TV technology helps reduce the bandwidth requirementfor each program, and the spectrum efficiency increases greatly. With the


spectrum saving from DTV broadcasting, broadcasters can use the savedspectrum to either provide more TV programs or offer new services.

3. Easy to Encrypt and Support Interactive Services. DTV systems can beextended from a point-to-multipoint broadcasting system to a point-to-pointinteractive system to support value-added services so that the user can eitherwatch TV programs or search/exchange information based on personal prefer-ences. Digitization in the whole process also facilitates the encryption, andexisting encryption techniques can be easily used in the DTV system.

4. Easy to Store, Process, and Distribute under Network Environment. Theadvantage of a DTV signal over its analog counterpart is that it is easy to store,process, and exchange. This facilitates the integrated transmission of images,data, and voice as well as TV program sharing under the network environment.

In summary, the introduction of the DTV concept relies on the latest technicalbreakthroughs from video compression and information transmission/processing. Thedigital video compression coding technique is applied to the video source to minimizeredundancy with high compression ratio at no (or almost no) loss in quality. Thetransmission data rate for any TV program is therefore reduced and the transmissionefficiency of the whole system is improved. Using error correction coding technologywhich introduces certain redundancy to the compressed information sequence and thehighly efficient digital modulation technologies, better transmission performance inthe presence of noise, interference, and other nonperfect conditions can be achieved.Also, due to the latest development in drive and display technologies, DTV systemscan surely offer better viewer experience, including sharper images, better color, andmore exquisite sound quality, all with improved spectral efficiency.

Looking forward, ultrahigh-definition TV (UHDTV) with UHDTV-1, represent-ing 4K of 3840× 2160, and UHDTV-2, representing 8K of 7680× 4320, systemshave been proposed by NHK Science & Technology Research Laboratories andare accepted by the International Telecommunication Union (ITU) [2]. DefinitelyUHDTV will be one development trend from the display point of view, while three-dimensional (3D) TV technologies following the recent popularity of 3D movies willbe another clear trend for the display. From the users’ experience point of view,intelligent TV systems will surely attract more and more people due its greatsimplicity and interactive capability. With the massive development of DTV networksand the increasing number of DTV users, various systems and applications for DTVhave been and will continue to be introduced.

There are three types of TV broadcasting networks regardless of whether they areanalog or digital: terrestrial (also known as over the air), cable, and satellite TVnetworks, as shown in Figure 1-1. Satellite TV broadcasting provides coverage of alarge area, especially in rural areas with sparse population while cable TV broad-casting uses the coaxial cable to deliver information to the home, with an emphasis onserving densely populated areas. As the most commonly used method of TVbroadcasting, the terrestrial system uses transmitting stations to send radio wavesover the air to cover certain service areas and users can receive TV programs by all

INTRODUCTION AND HISTORIC REVIEW 5

kinds of receiving antennas and various terminals. This makes it the most direct andreliable approach to reach people nationwide in case of emergency. Statistics showthat most people in the world still rely on terrestrial broadcasting networks to receiveTV programs, with the percentage in China over 60%. This book mainly focuses onthe core technologies and performance of the DTV terrestrial transmission system,which lay down the foundation for the various applications of DTV systems. The keyvideo compression concepts will also be introduced in this chapter.

It is generally acknowledged that the transmission environment for a satellite orcable channel is very similar to the ideal additive white Gaussian noise (AWGN)channel, and adoption of both advanced channel coding and modulation can make theperformance of both satellite or cable broadcasting approach the theoretical limit.Being the most commonly used DTV networks worldwide, the Digital TelevisionTerrestrial Broadcasting (DTTB) networks support the largest number of users. Theterm digital terrestrial television (DTTV or DTT) is also used to refer to the DTTBsystem, and they are used interchangeably within this book. The terrestrial broad-casting channel, however, presents the harshest transmission conditions due to thehigh degree of interference, especially with rapid changes in both time delay andamplitude of the multipath interference. This channel is far more complicatedcompared to that of either satellite or cable networks. The transmission environmentfor a terrestrial DTV broadcasting channel is obviously not an AWGN channel, andthis presents a great challenge for the DTTB system designer. Laboratory test resultsfor DTTB system performance under an AWGN environment may be significantlydifferent from that in the real world. In another words, the coding scheme with decentgain for an AWGN channel may not be applicable to the actual transmissionenvironment. Therefore, system performance should be carefully evaluated whenchoosing the appropriate transmission scheme not only in an AWGN channel but also

FIGURE 1-1 Classifications of DTV infrastructure.


in a multipath channel. Another important issue that needs to be addressed isinterference from the terrestrial broadcasting network itself. With the inevitablecoexistence of both analog and digital terrestrial TV services during the transitionperiod, the system must have strong capability to deal with both adjacent andcochannel interference from the analog transmission and also minimize its interfer-ence to the existing broadcasting systems (both analog and digital). This helpsguarantee the overall reception performance for all end users.

1.2 MAJOR INTERNATIONAL AND REGIONAL DTVORGANIZATIONS [3]

Almost all countries and regions have been or are now seriously considering thedeployment of DTV broadcasting networks based on the advantages the DTV systemcan provide. Countries such as the United States, Canada, United Kingdom,Germany, Japan, Netherlands, Finland, Switzerland, South Korean, and Swedenhave successfully completed their DTV transition (also known as the digital switch-over or analog switch-off) for their TV broadcast networks, while many countries inthe world are still in the process of transitioning their TV broadcasting networks fromanalog to digital.

1.2.1 International DTV Broadcasting Standards

Even though the application scenarios for terrestrial DTV broadcasting are verysimilar, different international transmission standards for DTTB systems have beenproposed, including ATSC (Advanced Television Systems Committee) by the UnitedStates, DVB-T (Digital Video Broadcasting-Terrestrial) by Digital Video Broad-casting organization, ISDB-T (Integrated Service Digital Broadcasting-Terrestrial) byJapan, and DTMB (Digital Terrestrial Television Multimedia Broadcasting) byChina. All four DTTB standards have been accepted by the ITU, and they havealready been commercialized in many countries and regions worldwide.

In the United States, the Federal Communications Commission (FCC) developedits own DTV broadcasting standard in 1987, which is required to be compatible withthe existing NTSC TV standard. In 1992, the ATSC, consisting of members whopassed its qualification and obtained authentication, was founded with the aim ofcreating advanced TV system standards. In the same year, ATSC put forward fourcandidate proposals, and eventually integrated them into a unified standard by GrandAlliance (GA) in 1995. This standard includes the AC-3 standard for multichannelaudio source coding and the MPEG-2 standard for video source coding, systeminformation, and multiplexing. The ATSC/8VSB describes a single-carrier system forterrestrial broadcasting with a throughput of 19.39Mbps when the system bandwidthis 6 MHz. The ATSC/16VSB is a standard for digital cable TV systems with totalthroughput of 38.78Mbps. The ATSC standard is generally believed to have a higherspectral efficiency and power efficiency but usually requires a better receivingenvironment. The FCC adopted ATSC as the DTV standard for the United States

MAJOR INTERNATIONAL AND REGIONAL DTV ORGANIZATIONS 7

on December 24, 1996, and revised it in 2009. H.264/AVC video coding wasintroduced to the ATSC system in 2008. All terrestrial TV broadcasters are requiredto deliver over-the-air TV programs using the ATSC standard, and even cableoperators are requested to carry ATSC signals from terrestrial broadcasters. ByJune 12, 2009, the United States had successfully replaced almost all analog NTSCTV system with ATSC. Canada and South Korea decided to use ATSC as well.

The European Launching Group (ELG) was founded in 1991 with the help of theGerman government. The ELG realized that mutual respect and trust had to beestablished between members and became the Digital Video Broadcasting (DVB)program in September 1993. Currently the DVB organization has more than 270members from nearly 40 countries, who are dedicated to the establishment of atechnical system for digital broadcasting systems. The DVB project provides a seriesof standard frameworks (DVB-C, DVB-S, and DVB-T) for digital video broadcastingsystems using different transmission media (e.g., coaxial cable, satellite, and terres-trial) and has announced over 60 DTV broadcasting standards which have beenaccepted worldwide. The DVB-S is the transmission standard for satellite digitalbroadcasting in which one analog TV channel which previously delivered one PALprogram can now support four DTV programs, and this greatly increases theefficiency of the satellite broadcasting system. The DVB-C is the transmissionstandard for DTV within the cable TV network in which one analog TV channelthat previously delivered one PAL program can now provide four to six DTVprograms. The DVB-T is the transmission standard for terrestrial digital broadcastingin which one analog TV channel that previously delivered one PAL program can nowprovide four to six DTV programs. DVB-T was first published in 1997, and the firstbroadcasting took place in the United Kingdom in 1998. These standards were alladopted by both the European Telecommunications Standards Institute (ETSI) andITU. Like the ATSC, the DVB also initially selects MPEG-2 as the standard foraudio and video source coding, system information, and multiplexing. Unlike ATSC,DVB-T is a multicarrier system which uses the coded orthogonal frequency divisionmultiplexing (C-OFDM) technology for transmission. Compared to the ATSC, theDVB-T can effectively support both fixed and mobile reception under a complicatedenvironment at very little expense of both spectral and power efficiencies and cansupport the single-frequency network application well. The extended application, themobile TV standard DVB-H, has also been introduced. So far, over 60 countries haveofficially chosen DVB-T as the terrestrial DTV transmission scheme and more than 30countries are now covered by DVB-T signals, among which some have finished theanalog switch-off.

DVB decided to study options for an upgraded DVB-T standard in March 2006and a formal study group named Technical Module on Next Generation DVB-T wasestablished to develop an advanced modulation scheme as the second-generationdigital terrestrial television standard in June 2006. In June 2008, DVB announced itssecond-generation DTTB standard, known as DVB-T2, and some countries andregions have shown strong interest in adopting it as it can provide more than 30%throughput than the first-generation DTTB standards. More details regarding DVB-T2 will be given in the following chapters.


The Japanese authority started the development of DTV broadcasting standards in1994. They have also decided to use MPEG-2 as the standard for source coding andsystem information. The core standards of ISDB, the Japanese standard, are ISDB-S(satellite), ISDB-T (terrestrial), and ISDB-C (cable). Similar to DVB-T, the develop-ers of the ISDB-T standard also chose OFDM as the modulation scheme, while usingfrequency segmentation to deliver both terrestrial and hand-held TV programs withinthe same 6-MHz frequency band. In other words, broadband and narrow-bandinformation is transmitted using the same facility and within the same channel forthe same coverage area, which greatly facilitates mobile reception by portabledevices. This mixed transmission scheme turns out to be a big success to supportmobile TV users. Japan finished its analog switch-off in 2012 and ISDB-T has alsobeen adopted in several countries and regions.

The effort on developing the Chinese DTTB standard was officially started in 1999through the call for proposals from the Chinese government. With several individualproposals being successfully merged in 2005 and an independent test by a third party,the Chinese national DTTB standard was approved by the Standardization Adminis-tration of the People’s Republic of China and announced on August 18, 2006 [4]. Thestandard is called “Framing Structure, Channel Coding andModulation for the DigitalTV Broadcasting System,” with an official label of GB20600-2006. The Englishtranslation is “Digital Television Terrestrial Multimedia Broadcasting (DTMB).”DTMB can satisfy various requirements of broadcasting services, such as HDTV,SDTV, and multimedia data broadcasting. It provides large-area coverage andsupports both fixed and as mobile reception. DTMB adopts both single- and multi-carrier modulation with a unique frame structure called time-domain synchronousOFDM (TDS-OFDM) and uses the low-density parity code (LDPC). It can thereforeprovide fast system synchronization, better receiving sensitivity, and excellent systemperformance against the multipath effect plus the advantage of high spectrumefficiency and flexibility for future extension. The massive deployment of DTMBin China started in 2008 [5] and DTMB became the ITU standard in 2011.

1.2.2 Related International and Regional Organizations

To overcome the engineering problems that arose from the development anddeployment of DTV networks and ensure smooth analog-to-digital migration,many international organizations have been working closely and developed a seriesof DTV-related frameworks and supporting standards. These standards cover all fieldsrelated to DTV broadcasting implementation, e.g., compression/decompression,coding/decoding, modulation, framing, frequency allocation, content encryption,conditional access, and signal distribution for the DTV signal. These organizationsthat have contributed significantly are as follows:

1. The Moving Image Experts Group (MPEG), a working group of the Interna-tional Organization for Standardization (ISO) and the International Electro-technical Commission (IEC), has the responsibility of developing thestandards for compression, decompression, and processing on video, audio,

MAJOR INTERNATIONAL AND REGIONAL DTV ORGANIZATIONS 9

and a combination of both. TheMPEG is a subsidiary organization of the ISO/IEC technical committees dedicated to standardizing the information technol-ogy related equipment.

2. The Multimedia and Hypermedia Information Coding Expert Group (MHEG)is another working group under the same subcommittee to which the MPEGbelongs. MHEG is dedicated to the coding of both multimedia and hypermediainformation by defining the encapsulation format for the multimedia docu-ments such that communication can be performed by a special data format.

3. The Digital Audio Video Council (DAVIC) was founded in Switzerland in1994 as an international, nonprofit organization with a membership of 220corporations from 25 countries. The DAVIC is dedicated to providing end-to-end interoperation standards for both digital video and audio between differentcountries and different applications and delivers open interface and protocolsfor digital services and applications.

4. The European Broadcasting Union (EBU) is a nongovernmental and nonprofitorganization. Any non-European broadcasting company can also become amember of EBU. It supports both DVB projects and the Digital TerrestrialTelevision Action Group (DigiTAG) as well as work by other standardgroups, e.g., European Committee for Electrotechnical Standardization (CEN-ELEC), ETSI, ITU, and IEC.

5. ITU, a subsidiary organization under the United Nations, is perhaps the mostimportant international standardization organization in both the tele-communication and radio communication fields in the world. It is a majorpublisher for telecommunication technologies, rules, and standards and isdedicated to spectrum management. The ITU Radiocommunication Sector(ITU-R) formulates the DTV broadcasting standards.

6. ETSI and the American National Standards Institute (ANSI) have made a jointeffort for the interconnection between video transmission circuits and tele-communication devices, and formulated two major standards: ETS 300 174(equivalent to ITU-T Rec. J. 81) and ANSI TI. 802.01. These two standardsdistribute a video channel to each bit stream and describe coding, multi-plexing, encryption, and network matching for the video channel so thatdevices are able to connect to the telecommunication devices directly. ETSIwas founded in 1988 aiming to help establish the unified telecommunicationmarket in Europe by formulating the related telecommunication standards.The ETSI technical committee formulated standards for interconnectionbetween public networks and private networks. ETSI’s multimedia Codecis used for the interconnection between the broadcasting networks and thetelecommunication networks. ANSI’s Codec is similar to ETSI’s Codecexcept for the audio interface and the SMPTE control function and hasgood connection to the telecommunication networks in the United States witha transmission rate of 45Mbps.

7. IEC is responsible for standardization of electrical equipment. ISO is anongovernmental international alliance for standardization responsible for


formulating industrial standards. Both ISO and IEC are dedicated to thestandardization of global personal and industrial equipment. They haveestablished many joint technical committees in these fields.

8. The JTC 1 (Joint Technical Committee formed by the ISO and IEC) aims atformulating standards for information technology related equipment. JTC 1establishes a subsidiary organization with the acronym of MPEG to formulatestandards for digital video coding and audio compression equipment asdescribed above.

9. The DigiTAG was founded in 1996 and is dedicated to creating a frameworkfor digital terrestrial television applications in accordance with DVB-Tspecifications. The DigiTAG has around 40 members from 14 countriesand is managed through EBU.

10. CENELEC was founded in 1973 and is a nonprofit European organization forelectrotechnical standardization. CENELECmembers are the national electro-technical standardization bodies of most European countries. They arededicated to solving the integration issues between the member states ofthe European Commission (EC). CENELEC cooperates with technical expertsfrom 19 EC and European Free Trade Association (EFTA) member states toprepare voluntary standards which help facilitate trade between countries,create new markets, cut compliance costs, and support the development of asingle European market. CENELEC also works closely with other technicalcommittees in fields such as television and cable classification.

1.3 COMPOSITION OF DTV SYSTEM

1.3.1 Constitution of DTV System

A complete DTV broadcasting system consists of three key components; the trans-mitting head-end system, transmission system/distribution network, and user terminalsystem.

1.3.1.1 Transmitting Head-End System for DTV Broadcasting A transmittinghead-end system for DTV broadcasting refers to the professional equipment for theTV station, and it mainly comprises the video cameras, video recorders, storagedevices, special effect machines, editing machines, subtitling machines, audio andvideo encoders. Considering MPEG-2 has been used and is still used for videocompression by most of DTV standards currently, MPEG-2 will be used as anexample for the following discussion. The equipment is mainly used for sourceprocessing, information processing, storage, and play as well as other functionalities.

The source processing unit usually includes audio and video encoders, an adaptor,a data encapsulation device, a VOD (video on demand) system, and an editingprocessor. The MPEG encoder compresses and encodes the recorded audio and videosignals into MPEG-2 format; the adaptor adaptively receives MPEG-2 signals fromother networks such as synchronous digital hierarchy (SDH) and satellite and then

COMPOSITION OF DTV SYSTEM 11

sends them to the multiplexers for multiplexing purposes or to the program librariesfor storage as well as further editing; the data encapsulation device helps packetize theInternet Protocol (IP) data and data in other formats used for data broadcasting as wellas interactive services into signal format for DTV broadcasting and transmits thesesignals together with other signals to the users; the VOD system sends the programsand information requested by users; the editing processor edits and helps manage thestored digital programs.

The information processing unit usually comprises the program schedulingsystem, the user management system, the multiplexer, and the conditional access(CA) system. The program scheduling system is a platform for the service manage-ment and system applications. The user management system is responsible forhandling users’ account information. The multiplexer is the core part of the unitand is responsible for content scheduling, including reselection, allocation, multi-plexing, and distribution of the contents gathered from different places to differentchannels with control of the program scheduling system. CA applies the encryptionmechanism to the different program contents via a scrambler and multiplexer so thatthe program contents are encrypted according to different time periods and usergroups according to service modes and user demands. As a new and attractive serviceof DTV broadcasting, an electric program guide (EPG) helps provide more programinformation to the end users by inserting the corresponding information into a real-time bit stream at the head end.

1.3.1.2 Transmission System/Distribution Network for DTV Broadcasting Thetypical networks for transmitting and distributing the DTV signals include terrestrialbroadcasting, cable, and satellite.

Statistics show that terrestrial broadcasting is still the most important and popularTV broadcasting scheme. To accommodate the most complicated transmissionenvironment for terrestrial broadcasting, the technologies and functional blocks inthe DTTB system are different not only from that of the analog television but alsopossibly from that of satellite or cable DTV broadcasting. The terrestrial broadcastingtransmission network mainly comprises the SFN adapters, exciters, and transmitters.

Cable TV is the major TV transmission method in densely populated regions suchas metropolitan areas. Because the signal is sent through a coaxial cable, a very stablequality of signal transmission with a large number of programs can be supported.Cable DTV is also convenient to offer pay-per-view (PPV), VOD, and otherbidirectional as well as value-added services.

Satellite TV provides large coverage and its signals can be received in urban,suburban, and rural areas if there exists a line-of-sight (LOS) path between the satelliteand the receiving antenna. The equipment in a satellite TV transmission networkmainly comprises the satellite modulators, RF power amplifiers, and satellitetransponders.

1.3.1.3 User Terminal System for DTV Broadcasting In the DTV era, either adigital TV set or a set-top box (STB) matching the analog TV set is needed to watchDTV programs, and STB is very popular due to its low cost and user convenience
